Pump



Oct. 8, 1968 y L, iQQcoNNL-:LLY 3,404,633

. /NvENToR AVER/V RI CUNA/UY BY QM/ M9 ATTORNEYS O ct. 8, l1968 R. CONNELLY 3,404,633

' PUMP y Filed Sept.. 16, 1966 2 Sheets-Sheet 2 /NVENTOR LAI/EM A. CoA/Naw BY j ATTO/aways United States PatentO 3,404,633 PUMP Lavern R. Connelly, Marshall, Mich., assignor to Eaton Yale & Towne Inc., Cleveland, Ohio, a corporation of Ohio Filed Sept. 16, 1966, Ser. No. 579,906 3 Claims. (Cl. 10S- 136) `ABSTRACT OF THE DISCLOSURE The present invention relates to a pump, and more particularly relates to a pump constructed to relieve high uid pressure leakage to a shaft seal of the pump by communicating the seal area with a low pressure area.

An object of the present invention is the provision of a new and improved pump having a rotary pumping means driven by a shaft which is supported by bushings located on opposite sides of the pumping means and a seal surrounding the shaft at one end thereof to prevent leakage therepast and wherein leakage of fluid past the bushings supporting the shaft is at least in part directed through uid passageway means in the shaft to a low pressure region of the pump. p

A further object of the present invention is the provision of a new and improved pump, as noted in the a next preceding paragraph, wherein leakage of fluid past 'the bushing adjacent the seal is directed through radial openings in the shaftand through an axial passageway in the shaft which communicates with the pump inlet.

Another object of the present invention is the provision of a new 'and improved pump having a housing supporting a rotary pumping means which is driven by a shaft extending into an opening in the housing and sealing means is provided to effect a lluid seal between the driving shaft and the opening in the pump housing and wherein a llow passageway in the shaft directs high pressure fluid away from the sealing means to a low pressure region of the pump to thereby reduce fluid pressure adjacent thereto and minimize fluid leakage from the pump past the sealing means.

Yet another object of the present invention is the provision of la new and improved fluid pump including `a rotary pumping means and a driving shaft therefor supported in a housing by spaced bearings which are exposed to fluid at substantially pump discharge pressure, and wherein the driving shaft is provided with fluid conduit means terminating in a chamber communicating with an area adjacent `at least one of the bearings and with a fluid inlet of the pumping means to bleed high pressure uid leaking past the one bearing and into the chamber to the inlet of the pump.

Still :another object of the present invention is the provision of a new and improved pump, asset forth in the next preceding paragraph, and wherein lluid being bled to the pump inlet flows through a passageway fonmed in a support member Ifor one of the bearings.

Other objects and advantages of the present invention will become 'apparent from the detailed description thereof which follows, made with reference to the accompanying drawings and wherein:

rice

FIG. I1 is a fragmentary sectional view of a pump embodying the present invention, with a portion thereof in elevation; j p ,A

FIG. 2 is a fragmentary sectional view of a moditied pump embodying the present invention, with a portion thereof shown in elevation;

FIG. 3 is a fragmentary sectional view of the pump of FIG. l, taken approximately at line 3 3 of FIG. 1; and

FIG. 4 is a fragmentary sectional view of the pump of FIG. 2, taken approximately at line 4 4 of FIG. 24. j

A pump I10 embodying the present invention is shown in FIG. 1. The pump 10 is adapted to be associated with .an automotive vehicle, or the like, to provide high pressure fluid for a hydraulically actuated power steering system. It will become apparent, however, that a pump embodying the present invention may be suitably used in many other applications not associated with automotive vehicles.

The pump 10 includes a housing 11 which contains a i pumping means 12 therein. The pumping means 12 is suitably secured to a driving shaft 13 for rotation therewith. The shaft 13 is drivingly connected to an engine of the vehicle, which has not been shown.

The pumping `means 12 may be of any suitable construction, but is here shown as including an annular rotor or carrier [member 15 having a plurality of slots therein which carry pumping elements 16 and which is surrounded by a cam member 17. The cam member 17 has an inner cam surface 20 along which the pumping elements 16 move as the rotor or carrier 15 is rotated. The pumping elements 16 are preferably cylindrical roll members which are moved radially inwardly and outwardly relative to the rotor or carrier 15 by the cam surface 20 during rotation of the rotor. Adjacent pumping elements, or rolls 16, engage the cam surface 20 and the slots in the rotor or carrier 1:5 to form pumping pockets 21 therebetween. As the pumping elements move radially inwardly relative to the rotor 15, the volume of the pumping pockets 21 decreases, while movement of the pumping elements radially outwardly of the rotor or carrier 15 tends to reduce the pressure in the pockets. These radial movements of the pumping elements may be termed pumping strokes.

The pumping means 12 is positioned closely adjacent a cover member 25 which is fixed against rotation relative to the housing 11 by conventional means, which have not been shown. The cover member 25 supports a suitable bearing 26 `for supporting the shaft 13 for rotation relative to the cover 25. As here shown, the bearing 26 is a sleeve bearing xed in a closed cylindrical chamber 26a of the cover 25, best shown in FIG. 3. The cover 25 additionally includes inlet passageways 27 and discharge passageways 28 which communicate with the pumping pockets 21 at their inlet and discarge positions in the pumping means 12.

The pumping means 12 is positioned between the cover member 25 and an end plate 30. Suitable screws 31, only one of which is shown in FIG. 1, extend through an opening in the end plate 30 and the cam member 17 and are threadedly engaged in the cover 25 and secure these parts together. The end plate 30, cam mem-ber 17 and cover member 25 are maintained in radial alignment by a locating pin 32. In the illustrated embodiment, the end plate 30, the cam member 17, and the cover 25 are all :press fitted into the housing 11 so that they are fixed against rotation relative thereto. The end plate 30 suprports a suitable bearing 33 which supports the shaft 13 for rotation relative t-o the end plate .30. The bearing 33 is similar in construction to the bearing 26 and is lixed in the end plate.

The end plate 30 includes a body portion 40 which supports the bearing 33 at its inner periphery andwhich is in sealing engagement with the housing 11 at its outer periphery by means of a suitable O-ring seal 41. Additionally, a seal means 42 is provided for effecting a fluid seal between ,the b ody portion 40 and the shaft13. The seal means 42 may be of anysuitable construction, but ishere shownA as .a cartridge-type lip seal. `The end plate 3f)V also includes a radially extending'lflange` or web portion 45 having a forward surface 44 in close proximity to the 'rotor 15. The web portion 45 ofthe end plate 30 includes grooved portions 46,`FIG. 1, communicating with thexinlet of the pumping means 12 and`which also communicate with thearea around seal 42 by means of passageways 47 formed in the end plate 30. The end platen 30Vadditionally lincludes grooved portions 48a, FIG. 3, communicating with the discharge of the pumping means 12,'and'ports 48b which' communicate the discharge of the pumping means 124 with a chamber'49 formed by the housing`12 and the end plate 30. i

The area around the seal 42, the inlet passageways 47, and the area adjacent bearing 33 are in communication with the area adjacent bearing 26 in the cover member 25. This communication is provided by a central .passageway 50 formed in the shaft 13 and ports 52 in the shaft 13. The ports S2 communicate with the area around the seal and the inlet passageways47 and extend from the exterior of the shaft adjacent the seal to the passage- Iway 50 in the shaft. The passageway 50 opens at the end of the shaft 13 supported in the closed chamber 26a and thus communicates with chamber 26a. By this construction the passageway 50 freely receives any high pressure fluid leaking past the bearing 26 and into chamber 26a.

The passageways 47 formed in the end plate 30 are effective to direct high .pressure fluid in the region of the seal 42 back to the inlet of the pumping means 12. Thus, any high pressure fluid which leaks past the bearing 33 to the seal 42 is effectively directed to a low pressure area in the pump, namely, the inlet. Moreover, fluid leaking past the bearing 26 is also communicated to the passageways 47 through the passageway 50 and ports 52 in the shaft 13. In this manner, high pressure fluid leakage around bearing 26 is directed to the inlet of the pumping means 12. Moreover, since the area adjacent the seal 42 communicates with the inlet, a high pressure buildup in this area is prevented, thus the possibility of fluid leakage past seal 42 is greatly reduced.

Referring to FIG. 2, a pump is illustrated therein which is similar in most respects to the pump 10 illustrated in FIG. 1. The pump 10 differs from that previously described in that the body portion 40 of the end plate 30 terminates adjacent a flange 60 formed in the housing 11 and the seal formed between the housing 11' and the end plate 30 is effected by an O-ring 61 positioned between the end of the body portion 40' and the flange 60 of the housing 11. The O-ring 61, is of course, exposed to-fluid approximately at pump discharge pressure in the chamber 49 which is in communication with the pump discharge through the ports 48b, FIG. 4, and the end plate 30.

The flange 60 of the housing 11 is configured to receive a cartridge-type seal 42 which is effective to provide a fluid seal between the housing 11 and the shaft 13'. High pressure fluid which may leak past the O-ring seal 61 and the bearing 33 supported by the end plate 30 is directed from a chamber 63, FIG. 2, adjacent the seal 42 by conduit means including ports 52 in the shaft 13 and a central passageway 50 formed in the shaft 13. The ports 52 communicate with the chamber 63 adjacent the seal 42'. Fluid from the chamber 63 adjacent the seal 42 flows through ports 52 to the central passageway 50 of the shaft 13. The fluid in the passageway 50 then flows to the inlet of the pumping means 12 through ports 54 formed in the bearing support portion of the cover member 25 as indicated by arrows in FIG. 2. In this manner, the high pressure fluid in the region of 4 v the seal 42' is effectively drained or bled from the seal region into the inlet of the fpumping means 12'. It should be apparent that high pressure fluid leaking past the bearing 26 in the cover 25 is also returned to the inlet of the pumping means by the ports 54'.

While two preferred embodiments ofthe present invention-have been illustrated and described herein'in'considerable detail, the present invention is not-to be considered to be limited to the precise construction disclosed herein. It is my intention to cover hereby all modifications, adaptations, and changes of thedisclosed construction which come within the scope of the appended claims. Y

Having described my invention, I claim:

1. A fluid pump comprising a housing having a fluid inlet and a fluid outlet, a drive shaft projecting axially from said housing, seal means mounted in said housing in sealing engagement with an axially extending surface of said drive shaft for preventing leakage of fluid from said housing, first and second bearing means mounted in said housing along said drive shaft in an axially spaced apart relationship for supporting said drive shaft for rotation relative to said housing, carrier means xedly secured to said drive shaft intermediate said first and second bearing means, a plurality of pump elements Vassociated with said carrier means for rotation with said carrier means and drive shaft relative to said housing, cam means fixedly secured to said housing and located radially outwardly of said carrier means and pump elements for moving said pump elements in a generaly radial direction relative to said drive shaft upon rotation-of said drive shaft and carrier means relative to said cam means to thereby pump fluid from said fluid inlet to said fluid outlet, a chamber formed in said housing and connected in fluid communication with at least one of said bearings, first fluid passage means extending axially along said drive shaft and opening into said chamber at one end, a plurality of radialy extending passages formed in said drive shaft adjacent another end of said first fluid passage means, and second fluid passage means formed in said housing and connecting said plurality of radially extending fluid passages and said seal means in fluid communication with said fluid inlet for said housing, said second fluid passage means opening into said fluid inlet at a locaton adjacent to said carrier means and radially inwardly of said pump elements to thereby enable fluid leaking past said first and second bearing means to said chamber to be conducted through said radially extending passages, said first passage means and said second passage means to said fluid inlet and to thereby minimize fluid pressure on said seal means.

2. A fluid pump as set forth in claim 1 wherein said first passage means has a relatively large cross sectional area and each of said plurality of radially extending passages has a relatively small cross sectional area.

3. A fluid pump comprising a housing having a fluid inlet and a fluid outlet, a drive shaft projecting axially from said housing, seal means mounted in said housing in sealing engagement with an axialy extending surface of said drive shaft for preventing leakage of fluid from said housing, first and second bearing means mounted in said housing along said drive shaft in an axially spaced apart Arelationship for supporting said drive shaft for r0- tation relative to said housing, carrier means fixedly secured to said drive shaft intermediate said first and second bearing means, a plurality of pump elements associated with said carrier means for rotation with saidtcarrier means and drive shaft relative to said housing, cam means fixedly secured to said housing and located radially outwardly of said carrier means and pump elements for moving said pump elements in a generally radial direction relative to said drive shaft upon rotation of said drive shaft and carrier means relative to said cam means to thereby pump fluid from said fluid inlet to saidl fluid outlet, first chamber means formed in said housing and connected in fluid communication with said seal means tending passages formed in said drive shaft and opening at one end into said rst chamber means, first fluid passage means extending axially of said drive shaft, said plurality of radially extending passages opening at another end into said first fluid passage means adjacent one end of said first uid passage means, second chamber means formed in said housing at one end of said drive shaft and connected in fluid communication with one of said bearing means, said first fluid passage means opening into said second chamber means, second fluid passage means formed in said housing and opening into said second chamber means, said second fluid passage means including a plurality of passages which open into said fluid inlet at a location adjacent to said carrier means and radially inwardly of said pump elements to thereby enable lluid leaking into said rst and second chambers to be conducted through said plurality of radially extending passages, said first passage means, and said second passage means to said uid inlet and to thereby minimize uid pressure on said seal means.

References Citedl UNITED STATES PATENTS 2,684,034 7/1954 Roth 103-111 2,704,516 3/1955 Mock et al. 103-87 2,988,009 6/1961 Kraissl 103--126 3,073,251 1/1963 Weigert 103-126 3,167,020 1/1965 Rohde 103-42 X 3,207,077 9/1965 Zeigler et al. 103`42 3,236,566 2/1966 Halsey 103-136 X 3,240,158 3/1966 B'rundage 103-126 3,272,138 9/1966 Connoy et al 103-136 X 3,329,067 7/1967 Rosaen 103-136 X FRED C. MATTERN, JR., Prima/'y Examiner.

W. J. KRAUSS, Assistant Examiner. 

